1. Field of the Invention
The present invention relates to the field of computer implemented graphic image display. More particularly, the present invention relates to the field of computer implemented graphical user interfaces.
2. Related Art
FIG. 1 illustrates an exemplary electronic system 10 including a digital television receiver 12 coupled to a source of digital information such as the Internet or a digital broadcast medium 20. Under control from a software application program that is resident therein, the digital television receiver 12 is able to display a user interface (UI) 14 on a display screen. The user interface 14 contains graphical elements such as menu bars 20, buttons 16 and entry fields 18. The software environments being standardized for digital television receivers allow software application programs that are downloaded over broadcast transmissions ("broadcast applications") to construct graphical user interfaces 14 that are rendered by the digital television receiver 12. In general, the broadcast applications are foreign to the digital television receiver 12 and, as such, can be authored by vendors other than the vendor of the digital television receiver 12. Broadcast applications typically want to install and use their own user interfaces and have a rich programming environment at their disposal which provides them with much freedom in defining the look and feel of their user interfaces.
One problem in the prior art is that receiver vendors (manufacturers) also want some ability to influence the look and feel (e.g., the visual presentation and reaction to user events) of downloaded applications in order to provide a consistent and predictable experience for the user thereby making it easier for the user to interact with the receiver. In the above environment, the user interface of a broadcast application can conflict with the user interface appearance of the device vendor. In traditional windowing environments, the broadcast application's look and feel is determined largely by predefined user interface components, e.g., buttons, menus, window boarders, fields, etc., which are assembled and tailored by applications. The computer system platform of the receiver influences the look and feel first by specifying the APIs (Application Programming Interfaces) used to construct UI components and second by specifying the parameters, e.g., window border color, by which applications (or the user) may customize the appearance and behavior of UI components.
However, this approach is not viable in the proposed environments 10 (FIG. 1) for digital television receivers because broadcast applications may choose to ignore predefined UI components and can specify their own UI components. Since much of what then determines an application's visual appearance (look) and reaction to the user input (feel) is embedded in the logic of the broadcast application, it becomes very difficult for an entity residing on the receiver, such as an application manager, to influence the look and feel of an arbitrary application. What is desired is a mechanism that can allow a manufacturer to have some control over the look and feel of the user interface components of a digital television receiver, or similar electronic device, but yet is generic enough to be applied across many broadcast applications.
A second problem associated with the proposed environments 10 (FIG. 1) for digital television receivers is that applications using traditional windowing system concepts lack the dynamic graduation and dynamic multi-layered look that is generally associated with television graphics. What is needed, therefore, is a mechanism by which an application manager can enhance such applications with a more "TV friendly" look without interfering with the internal logic and programming of the broadcast applications.